Flame spread over electrical wire with applied AC electric fields

Mar 31 2016 03:00 PM
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Mar 31 2016 04:00 PM

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Photo Credit: Aurelie Ravon

On Thursday, March 31, the center hosted a seminar titled 'Flame spread over electrical wire with applied AC electric fields' by Prof. Jeong Park who is teaching at the Department of Mechanical Engineering at Pukyong National University.

Abstract

The
effect
of electric field on the characteristics of flame spread along a polyethylene
(PE) insulated electrical wire was investigated experimentally by varying the
AC frequency and voltage applied to the wire. The results showed that the flame
spread rate was accelerated due to the convergence of electric flux near the
end of wire, having three distinct regimes depending on applied voltage. In
each regime, several subregimes
could be identified depending on AC frequency. Flame shape (height and width)
and slanted direction of the spreading flame were influenced differently.
Fuel-vapor jets were ejected from the molten PE surface even for the baseline
case without the application of an electric field; this could be attributed to
the bursting of fuel vapor bubbles generated from internal boiling at the
molten PE surface. An internal circulation of molten-PE was also observed as a
result of non-uniform heating by the spreading flame. In the high voltage
regime with a high AC frequency, excessive dripping of molten PE led to flame
extinction.

Bio

Jeong Park
holds
a B.S. degree in Mechanical Engineering from the Seoul National University
(1987) and M.S. (1990) and Ph.D (1995) degrees in Mechanical Engineering
from the Korea Advanced Institute of Science and Technology. He was a post
doctoral research associate at the Korea Advanced Institute of Science and
Technology (1997-1999) and a guest researcher at the Tohoku University in Japan
(1997-1998). He then joined the Korea Aerospace Research Institute as a senior
researcher (1999-2000). He taught and studied the general area of flame
structure in combustion field and rocket propulsion system (2000-2006) at Sunchon
National University. He was a guest scientist at National Institute of Science
and Technology in U.S.A. (2004-2005). He joined the Department of
Mechanical Engineering at Pukyong National University in 2007.